Battery packs, systems, and methods having improved thermal management

Abstract

Battery packs, systems, and methods of implementing improved thermal management are described. A battery pack may include a cell holder, an inlet disposed proximate to a first end of the cell holder, an outlet disposed proximate to a second end of the cell holder, and a fluid flowing between the inlet and the outlet. A first battery cell may be disposed adjacent to a second battery cell in the cell holder. A structure may be disposed in a gap between the first battery cell and the second battery cell. The structure may direct the fluid towards a first circumferential edge of the first battery cell and a second circumferential edge of the second battery cell.

What is claimed is: 
     
         1 . A battery pack, comprising:
 a cell holder;   an inlet disposed proximate to a first end of the cell holder;   an outlet disposed proximate to a second end of the cell holder;   a fluid flowing between the inlet and the outlet;   a first battery cell disposed in the cell holder;   a second battery cell disposed adjacent to the first battery cell in the cell holder; and   a structure disposed in a gap between the first battery cell and the second battery cell,
 wherein the structure is configured to direct the fluid towards a first circumferential edge of the first battery cell and a second circumferential edge of the second battery cell. 
   
     
     
         2 . The battery pack of  claim 1 , wherein the structure is a columnar structure projecting from a surface of the cell holder. 
     
     
         3 . The battery pack of  claim 1 , wherein the structure is a mesh structure. 
     
     
         4 . The battery pack of  claim 1 , wherein the structure comprises a length, and
 wherein a thickness of the structure varies along the length.   
     
     
         5 . The battery pack of  claim 1 , wherein the structure comprises one of:
 a triangular cross-section;   a square cross-section;   a circular cross-section; and   a hexagonal cross-section.   
     
     
         6 . The battery pack of  claim 1 , wherein the inlet and the outlet are formed in opposing sidewalls of the cell holder, and
 wherein an inlet axis is aligned with an outlet axis.   
     
     
         7 . The battery pack of  claim 6 , wherein the fluid comprises a thermal conductivity that is greater than 0.05 W/mk at 20° C. 
     
     
         8 . The battery pack of  claim 1 , further comprising a row of five or more battery cells,
 wherein the first battery cell and the second battery cell are provided in the row, and   wherein three or more structures are disposed around a majority of the five or more battery cells in the row.   
     
     
         9 . The battery pack of  claim 8 , wherein three or more structures are disposed around each of the five or more battery cells in the row. 
     
     
         10 . A battery system, comprising:
 a battery pack, comprising:
 a cell holder; 
 a plurality of battery cells disposed in the cell holder; and 
 a plurality of structures disposed in the cell holder,
 wherein a structure in the plurality of structures is disposed in a gap between adjacent battery cells in the plurality of battery cells, and 
 wherein the structure is configured to decrease a velocity of a fluid in the gap; 
 
   a pump configured to pump the fluid through the battery pack; and   a housing configured to house the battery pack and the pump.   
     
     
         11 . The system of  claim 10 , wherein each structure in the plurality of structures is disposed between at least three battery cells in the plurality of battery cells. 
     
     
         12 . The system of  claim 11 , wherein the plurality of battery cells and the plurality of structures are each arranged in a straight line. 
     
     
         13 . The system of  claim 11 , wherein the plurality of battery cells and the plurality of structures are each arranged in a zigzag pattern in which battery cells in the plurality of battery cells and structures in the plurality of structures alternate above and below a straight line. 
     
     
         14 . The system of  claim 10 , wherein each structure in the plurality of structures comprises one of:
 a triangular cross-section;   a square cross-section;   a circular cross-section; and   a hexagonal cross-section.   
     
     
         15 . The system of  claim 10 , wherein battery cells in the plurality of battery cells are rechargeable lithium-ion battery cells. 
     
     
         16 . The system of  claim 10 , further comprising a manifold connected to the pump, wherein the manifold is disposed outside of the battery pack for recirculating the fluid between the one or more outlets and the one or more inlets. 
     
     
         17 . A method of improving thermal management in a battery system, the method comprising:
 providing a battery pack, the battery pack comprising:
 an inlet; 
 an outlet; 
 a first battery cell disposed in a cell holder; 
 a second battery cell disposed adjacent to the first battery cell in the cell holder; and 
 a structure disposed in a gap between the first battery cell and the second battery cell; and 
   pumping a fluid through the inlet of the cell holder,
 wherein the structure is configured to decrease a velocity of the fluid. 
   
     
     
         18 . The method of  claim 17 , further comprising:
 pumping the fluid through the outlet; and   circulating the fluid through a manifold to move the fluid from the outlet to the inlet.   
     
     
         19 . The method of  claim 18 , further comprising:
 cooling the fluid circulating through the manifold.   
     
     
         20 . The method of  claim 18 , further comprising:
 charging the first battery cell and the second battery cell as the fluid is pumping through the inlet and the outlet.